code: def test_inplace_same_variable(self, xp):
      def impl(x, y, z):
          x += y
          x += y
  
      return impl
  
imports: import unittest
  from unittest import mock
  import cupy
  from cupy import testing
  from cupy_tests.core_tests.fusion_tests import fusion_utils
label_desc: Use image node_id 13 for calling the TestOptimizations obj's underlying member method code with example usage: obj.test_inplace_same_variable(xp) and returns: impl